The present invention relates to a device for measuring at least one electric variable of a current intended to flow in an electric apparatus. The invention also relates to an assembly comprising an electric apparatus and one such measuring device according to the invention.
It is known to manufacture measuring devices making it possible to measure electrical properties of a current passing through a circuit breaker, those measuring devices also being called electricity meters when they make it possible furthermore to calculate the electricity associated with a given current. Thus, document FR 2,977,323 A1 describes a measuring module provided for low-caliber circuit breakers and usable to update an existing electrical installation. This module comprises through holes making it possible to mount it around at least one electric conductor connected to the circuit breaker. Furthermore, it is known from document WO-2008/042483 A1 to manufacture a measuring module whose current sensor does not completely cover the conductor. However, with such a sensor, the measurement is sensitive to a lateral parasitic field. Furthermore, document EP 1,684,080 A1 reveals the use of an independent sensor mounted on each phase, self-powered by the current that passes through the conductor and communicating the value of the measured current by radio.
These different measuring systems measure electrical properties of a current flowing in the circuit breaker by positioning at least one current sensor around at least one electric conductor connected to the circuit breaker. The mounting of such measuring devices is therefore necessarily done in at least two steps, a first step consisting of fastening the electric conductor(s) on each terminal of the circuit breaker, after having passed them through the measuring module. A second step consists of fastening the measuring module to the circuit breaker. The installation of these measuring modules is therefore relatively complex, may cause mounting errors and may be made difficult by a lack of space.